7,210 results match your criteria chromatid exchange

High Resolution View on the Regulation of Recombinase Accumulation in Mammalian Meiosis.

Front Cell Dev Biol 2021 24;9:672191. Epub 2021 May 24.

Department of Developmental Biology, Erasmus MC, Rotterdam, Netherlands.

A distinguishing feature of meiotic DNA double-strand breaks (DSBs), compared to DSBs in somatic cells, is the fact that they are induced in a programmed and specifically orchestrated manner, which includes chromatin remodeling prior to DSB induction. In addition, the meiotic homologous recombination (HR) repair process that follows, is different from HR repair of accidental DSBs in somatic cells. For instance, meiotic HR involves preferred use of the homolog instead of the sister chromatid as a repair template and subsequent formation of crossovers and non-crossovers in a tightly regulated manner. Read More

View Article and Full-Text PDF

Vasa expression is associated with sex differentiation in the Asian yellow pond turtle, Mauremys mutica.

J Exp Zool B Mol Dev Evol 2021 Jun 8. Epub 2021 Jun 8.

Key Laboratory of Tropical & Subtropical Fishery Resource Application & Cultivation of Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.

Vasa, one of the best-studied germ cell markers plays a critical role in germ cell development and differentiation in animals. Vasa deficiency would lead to male-specific sterility in most vertebrates, but female sterility in the fly. However, the role of the vasa gene involved in germ cell differentiation is largely elusive. Read More

View Article and Full-Text PDF

Differential effects of cisplatin combined with the flavonoid apigenin on HepG2, Hep3B, and Huh7 liver cancer cell lines.

Mutat Res 2021 Jun 24;866:503352. Epub 2021 Mar 24.

Laboratory of Experimental Surgery and Surgical Research, Faculty of Medicine, Democritus University of Thrace, Alexandroupolis, 68 100, Greece; Postgraduate Program in Hepatobiliary and Pancreatic Surgery, 2nd Department of Surgery, Faculty of Medicine, Democritus University of Thrace, Alexandroupolis, 68 100, Greece.

The potential of apigenin (APG) to enhance cisplatin's (CDDP) chemotherapeutic efficacy was investigated in HepG2, Hep3B, and Huh7 liver cancer cell lines. The presence of 20 μM APG sensitized all cell lines to CDDP treatment (degree of sensitization based on the MTT assay: HepG2>Huh7>Hep3B). As reflected by sister chromatid exchange levels, the degree of genetic instability as well as DNA repair by homologous recombination differed among cell lines. Read More

View Article and Full-Text PDF

PARP1 modulates telomere sister chromatid exchange and telomere length homeostasis by regulating telomere localization of SLX4 in U2OS cells.

Life Sci 2021 May 1;277:119556. Epub 2021 May 1.

Department of Biochemistry & Biophysics, University of Kalyani, Kalyani 741235, India. Electronic address:

Objective: Poly(ADP-ribose) polymerase1 (PARP1) interacts and poly(ADP-ribosyl)ates telomere repeat binding factor 2 (TRF2), which acts as a platform to recruit a large number of proteins at the telomere. Since the discovery of TRF2-SLX4 interaction, SLX4 is becoming the key player in telomere length (TL) maintenance and repair by telomere sister chromatid exchange (T-SCE). Defective TL maintenance pathway results in a spectrum of diseases called telomeropathies like dyskeratosis congenita, aplastic anemia, fanconi anemia, cancer. Read More

View Article and Full-Text PDF

ASHLEYS: automated quality control for single-cell Strand-seq data.

Bioinformatics 2021 Apr 1. Epub 2021 Apr 1.

Institute for Medical Biometry and Bioinformatics, Heinrich Heine University, 40225 Düsseldorf, Germany.

Summary: Single-cell DNA template strand sequencing (Strand-seq) enables chromosome length haplotype phasing, construction of phased assemblies, mapping sister-chromatid exchange events and structural variant discovery. The initial quality control of potentially thousands of single-cell libraries is still done manually by domain experts. ASHLEYS automates this tedious task, delivers near-expert performance and labels even large data sets in seconds. Read More

View Article and Full-Text PDF

Genotoxicity linked to occupational exposure in uranium mine workers: Granzyme B and apoptotic changes.

Environ Sci Pollut Res Int 2021 Mar 12. Epub 2021 Mar 12.

Medical and Radiological Research Department, NMA, Cairo, Egypt.

Background: Uranium mining and processing are an ancient occupation, recognized as being grueling and accountable for injury and disease. Uranium (U) is a radioactive heavy metal used in many industrial applications. It increases the micronuclei frequencies as well as chromosomal aberration and sister chromatid exchange in peripheral blood lymphocytes. Read More

View Article and Full-Text PDF

Pold4, the fourth subunit of replicative polymerase δ, suppresses gene conversion in the immunoglobulin-variable gene in avian DT40 cells.

DNA Repair (Amst) 2021 Apr 1;100:103056. Epub 2021 Feb 1.

Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan. Electronic address:

The replicative polymerase δ (Polδ), consisting of four subunits, plays a pivotal role in chromosomal replication. Pold4, the smallest subunit of Polδ, is believed to contribute to the regulation of replication by facilitating repair in response to DNA damage. However, that contribution has not been fully elucidated. Read More

View Article and Full-Text PDF


Georgian Med News 2020 Dec(309):120-124

1Tbilisi State University, Department of Genetics; 2Tbilisi State University, Institute of Genetics; Georgia.

Following the completion of the Human Genome Project, the strategic direction of modern genetics has moved toward functional genomics, to explore the functions of non-coding regions of DNA. These non-coding regions are localized in heterochromatin. The functions of heterochromatin largely remain unclear. Read More

View Article and Full-Text PDF
December 2020

A Full Set of In Vitro Assays in Chitosan/Tween 80 Microspheres Loaded with Magnetite Nanoparticles.

Polymers (Basel) 2021 Jan 27;13(3). Epub 2021 Jan 27.

Departamento de Bioquímica y Medicina Molecular, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico.

Microspheres have been proposed for different medical applications, such as the delivery of therapeutic proteins. The first step, before evaluating the functionality of a protein delivery system, is to evaluate their biological safety. In this work, we developed chitosan/Tween 80 microspheres loaded with magnetite nanoparticles and evaluated cell damage. Read More

View Article and Full-Text PDF
January 2021

Genotoxicity induced in vitro by water-soluble indoor PM fractions in relation to heavy metal concentrations.

Environ Monit Assess 2021 Jan 23;193(2):82. Epub 2021 Jan 23.

Department of Genetics, Faculty of Medicine, Democritus University of Thrace, 68100, Alexandroupolis, Greece.

The aim of the present study was to examine the genotoxicity induced by water-soluble fractions of particulate matter (PM) and its potential relation with heavy metals. For this purpose, the genotoxicity induced on human peripheral lymphocytes by water-soluble PM (particles with aerodynamic diameter ≤ 2.5 μm) collected from the indoor air of various workplaces in Greece (n = 20), was examined by the Sister Chromatid Exchange (SCE) induction assay and assessed in relation to the concentrations of the heavy metals Cu, Pb, Mn, Ni, Co, Zn, Cr, and Cd. Read More

View Article and Full-Text PDF
January 2021

Synaptonemal complex formation produces a particular arrangement of the lateral element-associated DNA.

Exp Cell Res 2021 02 2;399(2):112455. Epub 2021 Jan 2.

Biología de Células Individuales (BIOCELIN), Laboratorio de Investigación en Patología Experimental, Hospital Infantil de México Federico Gómez, CDMX, Mexico. Electronic address:

During meiosis, homologous chromosomes exchange genetic material. This exchange or meiotic recombination is mediated by a proteinaceous scaffold known as the Synaptonemal complex (SC). Any defects in its formation produce failures in meiotic recombination, chromosome segregation and meiosis completion. Read More

View Article and Full-Text PDF
February 2021

Dcaf11 activates Zscan4-mediated alternative telomere lengthening in early embryos and embryonic stem cells.

Cell Stem Cell 2021 04 23;28(4):732-747.e9. Epub 2020 Dec 23.

Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital, Frontier Science Center for Stem Cells, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China; Tsingtao Advanced Research Institute, Tongji University, Qingdao 266071, China. Electronic address:

Telomeres play vital roles in ensuring chromosome stability and are thus closely linked with the onset of aging and human disease. Telomeres undergo extensive lengthening during early embryogenesis. However, the detailed molecular mechanism of telomere resetting in early embryos remains unknown. Read More

View Article and Full-Text PDF

and evaluation of clastogenicity of second-line antitubercular drug loaded PLGA nanoparticles.

Hum Exp Toxicol 2021 Jul 20;40(7):1064-1073. Epub 2020 Dec 20.

Department of Pharmacology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.

Sustained release nanoformulations of second line antitubercular drugs levofloxacin and ethionamide had shown promise in pharmacokinetics and acute and sub-acute toxicity studies. The present study evaluated the clastogenicity potential of the nanoformulations of these antitubercular agents. Clastogenicity was evaluated by (a) in vitro micronucleus assay (b) in vivo micronucleus assay in Swiss albino mice and (c) sister chromatid exchange (SCE) in CHO cell lines. Read More

View Article and Full-Text PDF

PrimPol-dependent single-stranded gap formation mediates homologous recombination at bulky DNA adducts.

Nat Commun 2020 11 17;11(1):5863. Epub 2020 Nov 17.

Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.

Stalled replication forks can be restarted and repaired by RAD51-mediated homologous recombination (HR), but HR can also perform post-replicative repair after bypass of the obstacle. Bulky DNA adducts are important replication-blocking lesions, but it is unknown whether they activate HR at stalled forks or behind ongoing forks. Using mainly BPDE-DNA adducts as model lesions, we show that HR induced by bulky adducts in mammalian cells predominantly occurs at post-replicative gaps formed by the DNA/RNA primase PrimPol. Read More

View Article and Full-Text PDF
November 2020

Alterations in telomere length and mitochondrial DNA copy number in human lymphocytes on short-term exposure to moderate hypoxia.

Toxicol Rep 2020 17;7:1443-1447. Epub 2020 Oct 17.

Department of Medical Genetics, School of Medicine, Keimyung University, Daegu, Republic of Korea.

Hypoxia is related to a variety of diseases, such as cardiovascular and inflammatory diseases and various cancers. Telomere length (TL) may vary according to the hypoxia level and cell types. To the best of our knowledge, no study has investigated the effect of moderate hypoxia on TL and mitochondrial DNA copy number (mtDNAcn) in human lymphocytes. Read More

View Article and Full-Text PDF
October 2020

Cytogenetic effects of antidiabetic drug metformin.

Drug Chem Toxicol 2020 Nov 8:1-8. Epub 2020 Nov 8.

Department of Biology, Science Faculty, Gazi University, Ankara, 06500, Turkey.

Metformin (MET) is the first-choice antidiabetic drug for type 2 treatment. In this study, the genotoxic potential of MET was evaluated by using chromosome aberrations (CAs), sister chromatid exchanges (SCEs), and micronucleus (MN) assays in human peripheral lymphocytes as well as comet assay in isolated lymphocytes. Human lymphocytes were treated with different concentrations of MET (12. Read More

View Article and Full-Text PDF
November 2020

Antigenotoxic and Antimutagenic Effects of , a Traditional Medicinal Herb against Genotoxicity of Cyclophosphamide: An Study on Human Peripheral Lymphocytes.

Prev Nutr Food Sci 2020 Sep;25(3):246-253

Department of Zoology, Government Arts College, Periyar University, Salem, Tamil Nadu 636007, India.

(family: Acanthaceae) is a medicinal herb-used in Indian system of medicine (Ayurveda, Siddha, and Unani), traditional and folk systems to treat various illnesses. This study examined the phytochemical constituents of ethanol extract from and its protective effect against genotoxicity caused by cyclophosphamide (CPA). Phytochemical screening and estimation of total phenolic content were analyzed using standard methods. Read More

View Article and Full-Text PDF
September 2020

A toxicological evaluation of a fulvic and humic acids preparation.

Toxicol Rep 2020 14;7:1242-1254. Epub 2020 Sep 14.

Toxi-Coop Zrt., Berlini utca 47-49, H-1045 Budapest, Hungary.

Humic substances are ubiquitous in soils and waters. These complex superstructures are derived from the decomposition of dead plant and animal matter and are vital to soil health. Their heterogenous composition is specific to their site of origin and is comprised of weakly bound aggregates of small organic compounds that can sequester minerals and make them available to plants. Read More

View Article and Full-Text PDF
September 2020

Evaluating the Genotoxic and Cytotoxic Effects of Thymidine Analogs, 5-Ethynyl-2'-Deoxyuridine and 5-Bromo-2'-Deoxyurdine to Mammalian Cells.

Int J Mol Sci 2020 Sep 10;21(18). Epub 2020 Sep 10.

Department of Environmental & Radiological Health Sciences, Colorado State University, Fort Collins, CO 80526, USA.

BrdU (bromodeoxyuridine) and EdU (ethynyldeoxyuridine) have been largely utilized as the means of monitoring DNA replication and cellular division. Although BrdU induces gene and chromosomal mutations and induces sensitization to photons, EdU's effects have not been extensively studied yet. Therefore, we investigated EdU's potential cytotoxic and mutagenic effects and its related underlying mechanisms when administered to Chinese hamster ovary (CHO) wild type and DNA repair-deficient cells. Read More

View Article and Full-Text PDF
September 2020

Regulation of telomeric function by DNA methylation differs between humans and mice.

Hum Mol Genet 2020 11;29(19):3197-3210

Department of Genetics, Rappaport Faculty of Medicine and Research Institute, Technion, Haifa 31096, Israel.

The most distal 2 kb region in the majority of human subtelomeres contains CpG-rich promoters for TERRA, a long non-coding RNA. When the function of the de novo DNA methyltransferase DNMT3B is disrupted, as in ICF1 syndrome, subtelomeres are abnormally hypomethylated, subtelomeric heterochromatin acquires open chromatin characteristics, TERRA is highly expressed, and telomeres shorten rapidly. In this study, we explored whether the regulation of subtelomeric epigenetic characteristics by DNMT3B is conserved between humans and mice. Read More

View Article and Full-Text PDF
November 2020

Genotoxic properties of materials used for endoprostheses: Experimental and human data.

Food Chem Toxicol 2020 Nov 1;145:111707. Epub 2020 Sep 1.

Institute of Cancer Research, Department of Internal Medicine I, Medical University of Vienna, 1090, Borschkegasse 8A, Vienna, Austria. Electronic address:

Approximately 2 million endoprostheses are implanted annually and metal ions as well as particles are released into the body from the materials which are used. This review describes the results of studies concerning genotoxic damage caused by artificial joints. DNA damage leads to various adverse long-term health effects in humans including cancer. Read More

View Article and Full-Text PDF
November 2020

Homologous chromosome pairing in meiosis of higher eukaryotes-still an enigma?

J Sybenga

Genome 2020 Oct 31;63(10):469-482. Epub 2020 Aug 31.

Laboratory of Genetics, Wageningen University, Wageningen, the Netherlands.

Meiosis is the basis of the generative reproduction of eukaryotes. The crucial first step is homologous chromosome pairing. In higher eukaryotes, micrometer-scale chromosomes, micrometer distances apart, are brought together by nanometer DNA sequences, at least a factor of 1000 size difference. Read More

View Article and Full-Text PDF
October 2020

Warsaw Breakage Syndrome associated DDX11 helicase resolves G-quadruplex structures to support sister chromatid cohesion.

Nat Commun 2020 08 27;11(1):4287. Epub 2020 Aug 27.

Section of Oncogenetics, Cancer Center Amsterdam and Department of Clinical Genetics, Amsterdam University Medical Centers, De Boelelaan 1118, 1081, HV, Amsterdam, the Netherlands.

Warsaw Breakage Syndrome (WABS) is a rare disorder related to cohesinopathies and Fanconi anemia, caused by bi-allelic mutations in DDX11. Here, we report multiple compound heterozygous WABS cases, each displaying destabilized DDX11 protein and residual DDX11 function at the cellular level. Patient-derived cell lines exhibit sensitivity to topoisomerase and PARP inhibitors, defective sister chromatid cohesion and reduced DNA replication fork speed. Read More

View Article and Full-Text PDF

EdU-Based Step-by-Step Method for the Detection of Sister Chromatid Exchanges for Application in Plant Genotoxicity Assessment.

Front Plant Sci 2020 24;11:1146. Epub 2020 Jul 24.

Plant Cytogenetics and Molecular Biology Group, University of Silesia in Katowice, Katowice, Poland.

This study is an example of using 5-ethynyl-2'-deoxyuridine (EdU) for detecting sister chromatid exchanges (SCEs) at chromosomal level. Here we report a detailed protocol for differential labeling sister chromatids in barley (, 2n = 14) cells that is based on the incorporation and simple detection of EdU. The perfect distinguishing of sister chromatids enabled an analysis of the effects of two model agents-maleic acid hydrazide (MH) and gamma rays-on the formation of SCEs. Read More

View Article and Full-Text PDF

The Sister-Chromatid Exchange Assay in Human Cells.

Methods Mol Biol 2021 ;2153:383-393

Centro Andaluz de Biología Molecular y Medicina Regenerativa, CABIMER, Universidad de Sevilla-CSIC-UPO, Seville, Spain.

The semiconservative nature of DNA replication allows the differential labeling of sister chromatids that is the fundamental requirement to perform the sister-chromatid exchange (SCE) assay. SCE assay is a powerful technique to visually detect the physical exchange of DNA between sister chromatids. SCEs could result as a consequence of DNA damage repair by homologous recombination (HR) during DNA replication. Read More

View Article and Full-Text PDF

Holliday Junction Resolution.

Methods Mol Biol 2021 ;2153:169-185

Departamento de Bioquímica e Bioloxía Molecular, CIMUS, Universidade de Santiago de Compostela-Instituto de Investigación Sanitaria (IDIS), Santiago de Compostela, Spain.

Holliday junctions are four-way DNA structures that may arise during meiotic recombination, double-strand break repair, or postreplicative repair by the reciprocal exchange of single strands between two DNA molecules. Given their ability to effectively bridge two sister chromatids or homologous chromosomes, cells have implemented various pathways to ensure their timely removal. One of them is the nucleolytic processing of the Holliday junctions by specialized structure-selective endonucleases termed resolvases, which sever the connection between the linked molecules. Read More

View Article and Full-Text PDF

Integrative Analysis of Three Novel Competing Endogenous RNA Biomarkers with a Prognostic Value in Lung Adenocarcinoma.

Biomed Res Int 2020 4;2020:2837906. Epub 2020 Aug 4.

Department of Respiratory Medicine, The Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University, Huai'an, Jiangsu, China.

Increasing evidence has shown competitive endogenous RNAs (ceRNAs) play key roles in numerous cancers. Nevertheless, the ceRNA network that can predict the prognosis of lung adenocarcinoma (LUAD) is still lacking. The aim of the present study was to identify the prognostic value of key ceRNAs in lung tumorigenesis. Read More

View Article and Full-Text PDF

A Structure-Based Mechanism for DNA Entry into the Cohesin Ring.

Mol Cell 2020 09 4;79(6):917-933.e9. Epub 2020 Aug 4.

Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK. Electronic address:

Despite key roles in sister chromatid cohesion and chromosome organization, the mechanism by which cohesin rings are loaded onto DNA is still unknown. Here we combine biochemical approaches and cryoelectron microscopy (cryo-EM) to visualize a cohesin loading intermediate in which DNA is locked between two gates that lead into the cohesin ring. Building on this structural framework, we design experiments to establish the order of events during cohesin loading. Read More

View Article and Full-Text PDF
September 2020

Haspin kinase modulates nuclear architecture and Polycomb-dependent gene silencing.

PLoS Genet 2020 08 4;16(8):e1008962. Epub 2020 Aug 4.

Institut de Biologia Molecular de Barcelona, IBMB-CSIC, Barcelona, Spain.

Haspin, a highly conserved kinase in eukaryotes, has been shown to be responsible for phosphorylation of histone H3 at threonine 3 (H3T3ph) during mitosis, in mammals and yeast. Here we report that haspin is the kinase that phosphorylates H3T3 in Drosophila melanogaster and it is involved in sister chromatid cohesion during mitosis. Our data reveal that haspin also phosphorylates H3T3 in interphase. Read More

View Article and Full-Text PDF

Occupational benzene exposure and the risk of genetic damage: a systematic review and meta-analysis.

BMC Public Health 2020 Jul 15;20(1):1113. Epub 2020 Jul 15.

Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, Jiangsu Province, People's Republic of China.

Background: Benzene, an important component of organic solvents, is commonly used in industry. Meanwhile, benzene is a human carcinogen leading to leukemia. Although the links between benzene and various types of genetic damage indicators have been evaluated in several studies, but their results remain inconsistent. Read More

View Article and Full-Text PDF